gistfile1.txt

import MyTuple

import Control.Applicative
import Database.Record
import Database.Record.ToSql
import Database.Relational.Query
import Database.HDBC (SqlValue)
import Database.HDBC.Query.TH

instance ProductConstructor (a -> b -> c -> MyTuple a b c) where
  productConstructor = MyTuple

instance (FromSql SqlValue a, FromSql SqlValue b, FromSql SqlValue c)
         => FromSql SqlValue (MyTuple a b c) where
  recordFromSql = MyTuple <$> recordFromSql <*> recordFromSql <*> recordFromSql

instance (ToSql SqlValue a, ToSql SqlValue b, ToSql SqlValue c)
         => ToSql SqlValue (MyTuple a b c) where
  recordToSql = createRecordToSql (\(MyTuple a b c) -> fromRecord a ++ fromRecord b ++ fromRecord c)